Sealed vacuum package and article



Aug. 4, 1970 I w. E. YOUNG 3,522,879

SEALED VACUUM PACKAGE AND ARTICLE Original Filed Nov. 18, 1964 2Sheets-Sheet 1 K E X 07 WT W65?"m7" 'J! a J% [M|1HH "QM U s I NVENTOR.ML UAW f. yam/6 ATTORNEYS W. E. YOUNG SEALED VACUUM PACKAGE AND ARTICLEAug. 4, 1970 2 Sheets-Sheet 2 Filed Dec. 22. 1967 All it. i

I N\ EN TOR. MAL/AM E. Vow/G United States Patent 3,522,879 SEALEDVACUUM PACKAGE AND ARTICLE William E. Young, 52 Sea Beach Drive,Stamford, Conn. 06902 Continuation-impart of application Ser. No.662,838,

June 29, 1967, which is a continuation of application Ser. No. 412,063,Nov. 18, 1964. This application Dec. 22, 1967, Ser. No. 695,827

Int. Cl. B65d 73/00 U.S. Cl. 206-78 28 Claims ABSTRACT OF THE DISCLOSUREThe package blank is formed as shown with a peripheral support to hold athin flimsy piece of film smoothly and evenly in the sealing areaadjacent its periphery despite the rush of evacuated air past all theside edges of the film and is constructed with a barrier film which isstretch-formable so as to conveniently form a pocket portion forcontaining foodstuffs as in the final package.

This application is a continuation-in-part of copending application,Ser. No. 662,838, filed June 29, 1967, now abandoned which is acontinuation of copending application, Ser. No. 412,063, filed November18, 1964, now abandoned.

This invention relates to a package blank especially suited to be usedin practicing the method disclosed and claimed in copending patentapplication, Ser. No. 650,- 038, filed June 29, 1967, now abandoned. andto a novel vacuum package using the blank of the invention for enclosingand protecting foodstuffs in a sealed container. The package blank isused in and as a part of the method of producing a vacuum package byforming a seal around the periphery of top and bottom package portionsthrough the steps of affixing top and bottom barrier film portions torigid supports and thereafter using said rigid supports to hold thebarrier film in position during forming of a film portion, duringevacuation of the package area, during the subsequent closing of thepackage and while a seal is effected between the films, and theinvention ineludes the provision of a package portion that makespossible an optimal practice of the method, and which can itself beeasily and economically manufactured.

Vacuum packaging of cheese, processed meats and other items is agenerally well-developed art. According to one general practice, thevacuum packages are formed of a top and a bottom piece, each of whichincludes or comprises a plastic film barrier. One of these pieces istypically preformed into a cup to receive the foodstuff or simply drapedover and then tucked around the foodstuff. The outer circumference andperimeter areas of these top and bottom pieces are then placed oppositeto one another and the air evacuated from between them. Thecircumference areas are then pressed together and a seal formed. Oneproblem has been to position and maintain the circumference area of onethin film in a flat, aligned and wrinkle-free condition next to theother film or support during the period in which sealing is effected.

The difficulty of holding the film wrinkle-free during forming of a filmand during the evacuation of air within the package to an absolutepressure of 525 mm. Hg can be appreciated when it is realized that thesheets of film are only about .0O2-.003 inch thick. The present solutionof this problem is to provide packaging equipment which has means forpositioning the barrier film without wrinkling and then holding it inthis position during forming, evacuation and during the subsequentclosing of the package halves and sealing. In practice, these means arecomplicated and expensive.

Moreover, the present vacuum packaging means are 3,522,879 Patented Aug.4, 1970 not completely reliable in achieving a tight seal around theentire circumference of the yacuum package. It is of the utmostimportance to form a perfect seal since even a minute opening will allowair to leak in and cause the packaged foodstuffs to deteriorate. Thispresents a health hazard since there is a risk that this deteriorationwill be undetected in the home before the foodstuffs are consumed. Evenin those cases for which the deterioration is detected, there is anunfavorable consumer relation which makes it important to themanufacturer to insure that a perfect seal is obtained every time.

In brief summary and according to one example of the present invention,a bottom package portion is made of paperboard covered with a barriermaterial that may be adhered either as a coating or as a film lamina. Inview of the present disclosure it will be apparent to men skilled in theart that any rigid support material, such as, for an example, aself-supporting plastic, may be used as the equivalent of paperboard,either covered with or comprising a barrier material.

A top package portion includes a paperboard having an opening in itscentral portion. Another support material may be substituted. A barrierfilm is placed over the opening and adhered to the paperboardcircumference area around the opening. The barrier film is applied in aflat sheet as from a roll to the flat paperboard, and a smooth flatcircumference area of the film is thus achieved and maintained by thepaperboard support. The barrier film may be thermally stretch-formedthrough the central opening of the paperboard to form a cup portion toeventually receive the foodstuff to be packaged. The paperboard adheredto the circumference of the film will maintain the barrier film in asmooth, unwrinkled condition during this forming and afterwards whilethe film is being transported, positioned and held for sealing againstthe circumference area of the bottom barrier material.

The package blank and package of the invention allows a simple andreliable method for vacuum packaging to be utilized in packaging offoodstuffs. For example, the method is capable of being practiced byrelatively simple vacuum packaging equipment which does not have toprovide any means for positioning and holding a flimsy piece of barrierfilm in a flat and unwrinkled position around its circumference areawhile at the same time evacuating the air from within the film and pastthis circumference area.

By means of the invention, it is feasible to evacuate air from thepackage past all four sides simultaneously and to then seal the foursides simultaneously. The desirability of this simultaneous four-sidedevacuation and sealing has been suggested in the past but thedifiiculties of maintaining the film in an aligned and unwrinkledcondition have heretofore made it practically impossible to achievethese advantages in actual commercial operation.

Further objects will be apparent from the following detailed descriptionand drawings in which:

FIG. 1 is a front elevation of a bottom package portion;

FIG. 2 is a plan view of a top package portion;

FIG. 3 is a front sectional elevational taken generally along line 3-3in FIG. 2;

FIG. 4 is a front sectional elevation of a top package portion after ithas been preformed;

FIG. 5 is a plan view of an alternative top package portion;

FIG. 6 is a plan view of the alternative top package portion shown inFIG. 5 after it has been preformed;

FIG. 7 is an end sectional elevation of the alternative top packageportion after it has been preformed;

FIG. 8 is a schematic drawing of method steps for constructing a packageaccording to the invention and as they may be practiced by a machine.

The invention may be practiced in the following manner. For convenienceof reference, the two package portions will be arbitrarily referred toas top and bottom package portions.

A bottom piece for the package is prepared with a relatively stiff boardlayer 1 dimensioned to the approximate size of the finished package.This rigid board may be made of paperboard or any other non-toxic andsuitable material may serve as an equivalent. The board is rigid ascompared to a plastic barrier film, but it should be understood that itmay be flexible as compared, for example, to heavy cardboard.

A barrier film 2 is adhered to the paperboard over one surface thereof.This barrier film which by definition in this context is substantiallyimpermeable to the passage of air or oxygen may be laminated or coatedon the board and it may be made of a material such as vinylidenechloride, aluminum foil, or other material such as nylon havingsufficient barrier properties to serve in preserving the particularfoodstuff or other material to be packaged. If the barrier material filmis laminated to the board rather than applied as a coating, it may beaffixed to the paperboard with a solvent or other type of liquidadhesive. A sealant or adhesive material 3 is applied over the barrierelement 2 by any convenient method. This sealant material is requiredonly about the outer circumference area of the bottom barrier film butfor convenience the entire bottom area may be covered with a laminatedor coated layer of sealant material such as polyethylene. It should beunderstood that if a barrier film is used which itself has, or includesa lamination which has, sealant properties, it is unnecessary to apply aseparate sealant layer.

A blank 5 for the top piece of the vacuum package is prepared with arigid board 6 having an outer circumference portion with a centralopening 7. This board may be made of the same material as that used forthe bottom package portion or it may be made of a different and, forexample, a lighter or heavier piece of material. This top board may alsobe dimensioned to the approximate size of the finished package. Abarrier film 9, that is, a film which is substantially impermeable tothe passage of air or oxygen by definition as understood in the foodpackaging art, is juxtaposed and passed over the opening 7 and adheredto this paperboard support. The barrier film may be adhered or glued tothe paperboard only in the circumference area adjacent to its outerperiphery 8 which is to form the seal and need not be adhered to theboard immediately adjacent to the opening 7. This barrier film 9 may beconstructed of a substance of nylon, polyester or other formablematerial. If the foodstuffs to be packaged require a better barrier topreserve the foodstuffs against spoiling by oxygen, the film 9 mayinclude a coating or lamina of a material such as Saran which may be onthe side of the film away from the board. The film 9 may optionallycarry a sealant coating of a material such as polyethylene. The barrierfilm 9 need not extend to the outer perimeter of the paperboard 6 butmay be set back from that edge for economy in the use of the filmmaterial. The barrier film material 9 may also be used as the film forthe bottom package portion but it may be preferable to use a cheaperbarrier coating since the bottom board may serve as a substrate.

It has been found that the barrier film portion of the package blankprepared as described may be preformed with conventional vacuum and heatforming equipment so that the barrier film 9 forms a cup portion 10 thatextends through the paperboard support opposite to the side to which thefilm is adhered, as shown in FIG. 4. It is to be understood that apreformed piece may also be used for the bottom package portion.

According to another embodiment of the invention, the paperboard 6 forthe blank to be used in making the package top piece may be formed asshown in FIG. 5 with a side flap portion 10 and end flap portions 11.Alternatively, flap portions may be used on all four sides.

The flaps 10 and 11 provide additional stiffening and support for thepaperboard piece 6 during its handling and they make possible aserviceably rigid construction of that piece with a smaller outercircumference edge portion than would otherwise be feasible withlightweight paperboard. This, in turn, achieves a more compact package.The flaps are set at an angle to the circumference edge when the barrierfilm is formed into a cup which is open and accessible and then functionadjacent the cup portion to help support it.

It is a further development and part of this invention to provide arounded bearing surface along the edges of the opening of the topsupport member portion on the side toward the barrier film. This roundedsurface can be provided by various manufacturing techniques, butaccording to a preferred teaching of this invention, the rounded edge isformed not only on the edge but also for a short distance on oppositesides of the edge by bending of a flap which extends into the openingand which is integral with the top support member upwardly. When thisflap is formed of paperboard or equivalent material, the flexing takesplace in the area of the juncture and also extends slightly past thejuncture in each direction so that the radius of curvature of thebearing surface is actually larger than the radius of curvature whichcould be provided within the thickness of the paperboard support withoutthe use of flaps. Moreover, the radius of curvature is flared slightlyat each end. Preferably, this curved bearing surface is provided alongeach edge so that it will protect the barrier film from being tornduring handling or flexing of the finished package or product. It isparticularly important that the curved bearing surface be provided alongeach edge past which the barrier film is formed as the forming of thebarrier film past such edges is particularly critical. According to oneembodiment, the rounded bearing surface is provided about the entiresides of the opening on all the edge surfaces and the pocket in thebarrier film is formed by pulling the barrier film material uniformlypast and by these edges. Alternatively, it is possible to form thepocket by flexing the barrier film most against such edges as areprovided with a rounded bearing surface, and leaving the less criticalareas of the edge exposed.

In other words, it is to be understood that as the flaps are bent duringformation of the cup, they provide a rounded edge about which thebarrier film can be formed. The flap material at the junction of theflaps and the remainder of the board assumes a rounded shape in contrastto the sharp and often jagged edge left by conventional forming ofopenings, as by die-cutting. The rounded edges do not impede theformation of the barrier film into the cup as might a sharp edge nor isthere tearing of the barrier film at the edge during forming. It shouldbe understood that in heat forming, this critical edge portion-when thefilm is adjacent the paperboard supportis most diflicult to heat to theideal temperature due to stretching of the film or in subsequent flexingas may be incurred during handling.

In order to facilitate the bending of the flaps during formation of thebarrier film into a cup, and in order to satisfactorily bend smallflaps, the flaps can be precreased along the line about which the flapsare bent.

Preferably, the barrier film that forms the cup portion next to theangled flaps 10 and 11 is adhered to the flaps for added strength andsupport. It is most convenient if this can be done before forming, whenthe flaps 10 and 11 are flat and the film 9 is adhered to thecircumference edge portion of the similarly flat package piece 6. Thismethod, however, encounters the problem that at least some portion ofthe film, particularly in the vicinity of the ends of the flaps, mustmove relative to the rigid flaps during the forming of the cup. It ispossible to adhere the film to the flaps only in an area set back fromtheir ends, but this requires control and alignment of the area in whichthe adhesive is applied and it achieves only partial support of the cupportion in the finished package. For a preferable procedure, it has beenfound that the adhesive may be applied over the entire surface of thepiece 6 without alignment if a heat sensitive vinyl emulsion type glueis used. This glue allows a satisfactory creep between flap and film asthe cup portion is formed and thereafter provides good support betweenthem. Also, a glue or adhesive which is pressure sensitive can beusedi.e. a glue which will hold and support the film on the flap againstthese pressures encountered in handling but which, under theextraordinary pressure in forming, will let go and allow relativemovement between film and flap. Further, any other glue or adhesive of atype which is relatively low in shear so as to permit relative slidingbetween flap and film can also be used.

It has been found possible to use glues or adhesives which do not allowthe barrier film and flap to move with respect to each other duringformation of the cup provided only one flap or two non-adjacent flapsare used. In this practice, it is the film which is not restrainedagainst movement relative to the flap which is stretched to form thecup. Alternatively, in view of this teaching, it will be apparent to menskilled in the art that the flaps can be spaced apart from each other attheir adjacent edges so that there is a gap between them which permitsfree deformation and stretching of the film during the forming of thepockets.

It is a further teaching of the invention to provide a burstable blankwhich is formed as described and of a paperboard piece 6 with flapsexcept that the joints 12 between the side and end flaps 10 and 11,respectively, are not cut entirely through but instead are partially cutor weakened to leave, for example, one or more narrow bridges ofpaperboard across the joints to connect the ends of the flaps together.Such a construction will provide greater and more rigid support to theblank during its handling and up to the time that the cup portion ispreformed on the molding equipment. At this time, and under the pressureof the vacuum or other forming, it has been found that the ends willburst apart allowing the cup to be formed as though they had beenseparated from the beginning. As before, the barrier film may be adheredto the flaps 10, 11 an adequate distance back from the divisions 12 sothat a free and unsupported portion of the film will be available forstretching between the flap ends when they separate as the cup portionis formed. Alternatively and according to a further teaching of theinvention, a heat sensitive vinyl emulsion type glue may be used asdescribed above.

One method for making packages, if the top and bottom package portionshave been prepared as separate fiat sheets according to one embodimentof the present invention, is shown schematically in FIG. 8. An advantageof carrying out this method with the bottom package portion being on thebottom and transported horizontally is that the food product can bemaintained in position on this portion by gravity. By this method, abottom package portion 4 is delivered to a loading area from storagemeans as shown at 15. The foodstuffs to be packaged and, for example,shingled bacon 16 is then placed on the central portion of this bottompiece as shown at 19.

A blank 5 for the top portion is supplied from a storage means or amagazine as shown at 17. The paperboard support member is used toposition the film that passes under the opening 7 under a vacuum andstretch forming mold at 18 which forms cup portion 10 of film 9 upwardlythrough the paperboard opening. For the further invention, the moldingheat softens a vinyl emulsion type glue to permit relative movementbetween the film and flaps during the forming process and moldingpressure bursts paperboard flaps apart and sets them at an angle to theedge portion of the package piece to form and provide support for aportion of the cup. This preformed top piece is then placed over thefoodstuff and onto the bottom piece as shown at 26. The words top andbottom are used illustratively; the top foodstuff and the bottom packageportion could be supplied on top.

Both package portions are then placed in a chamber at 21, the paperboardsupport being used to align and position the top and bottom barrierfilms opposite to one another. A tack seal may be made to hold thesupports and film in aligned position for subsequent handling and duringevacuation for final sealing. These seals should be made in as small anarea as will serve this purpose so as to leave the substantialcircumference of the package open for evacuation. The seals may, forexample, be in two spot locations located in the middle of two oppositesides of the package, the seal being made, for example by pressing aspot heater bar against the paperboard support carrying the film barrierwith sealant. A tack seal allows the relative alignment of the top andbottom blanks to be subsequently maintained, for example, while thealigned blanks are handled prior to the peripheral sealing into apackage. The chamber is evacuated and air is simultaneously drawn outfrom between the top and bottom package portions past each of the foursides to give an absolute pressure of between 525 mm. Hg within thechamber and package for most food products. After evacuation, an inertor preservative gas may be introduced into the package. It should beunderstood that this introduction of gas does not alter the basic methodof packaging and reference to vacuum evacuation is intended to refer toand include not only vacuum evacuating but also vacuum evacuating andthen gas-filling. The paperboard supports are then relied upon to holdthe circumference areas of the barrier films smooth and flat while aseal is simultaneously made at the four sides within the vacuum chamberas by pressing a heater means against the paperboard support carryingthe film barrier with sealant. The chamber is then opened and thecompleted package is delivered as at 22.

While one method of making the package of the invention has beendescribed above, it is noted that other methods can also be used to makethe package. For example, where the top and bottom package blanks areprepared as above with a barrier film of a material which isstretch-formable without the application of heat, the use of heatforming equipment can be avoided in forming the package.

The invention has been described above for the production of top andbottom package portions of individual sheets of material. It is to beunderstood that in commercial practice, long sheets or rolls ofpaperboard and film may be laminated together to provide the packageportions, each having a smoothly and evenly supported circumference areaof barrier film material that will form the peripheral andcircumferential seal areas in the finished package. After preparation,the long sheets and rolls are cut into lengths as is necessary so thatone package portion may be positioned over the next package portion inmanufacture of the separate packages.

The invention is further pointed out in the following claims.

What is claimed is:

1. A half package part of blank construction for use in making agas-tight package comprising a substantially flat support member havinga circumferential edge area, an opening within said edge area and a flatstretch-formable barrier film adhered over said opening and completelyaround said circumferential edge area whereby the periphery of saidbarrier film is maintained in a smooth unwrinkled condition duringformation of a gas-tight package said barrier film being substantiallyimpermeable to the passage of air and oxygen, and at least one flapintegrally secured on said support member, said flap extending inwardlyof said edge area into the aperture in overlying relation to saidbarrier film to stiffen the package blank during handling.

2. A blank as set forth in claim 1 in which said flap is adhered to saidbarrier film.

3. A blank as set forth in claim 2 wherein a creepable glue adheres saidflap to said barrier film.

4. A blank as set forth in claim 1 wherein said barrier film has acup-shaped pocket portion extending through the aperture of said supportmember past the opposite surface thereof whereby said pocket portion isadapted to cover a foodstuff to be packaged.

5. A blank as set forth in claim 4 wherein said fiap extends inwardly ofand at an angle to said edge area into the aperture in supportingrelation with a portion of said pocket portion of said barrier film.

6. A blank as set forth in claim 5 wherein said barrier film isthermally stretch-formable and which further comprises a heat softenableglue between said flap and barrier film for permitting relative movementbetween said barrier film and flap during formation of said pocketportion of said barrier film.

7. A blank as set forth in claim 5 wherein said cup portion is open andaccessible for insertion of foodstuffs thereinto.

8. A blank as set forth in claim -1 wherein said support member has atleast two flaps thereon projecting into said opening, each said flapbeing attached along a side edge of said edge area adjacent said openingand being affixed to an adjacent flap at at least one end thereof in aperforated-like burstable construction whereby a cup portion may beformed by bursting said flap ends apart, and bending said flaps at anangle and, stretching said barrier film.

9. A blank as set forth in claim 1 wherein said flap is precreased alongsaid edge area.

10. A package blank construction including a barrier film for use in themanufacture of a package having a circumferential seal formed betweenthe barrier film and another package part that comprises a supportmember; said support member having a circumferential edge area and anopening within said edge area; at least two flaps attached to thecircumferential edge area of said support member and extending into theopening, said flaps being adjoined by being attached to one another attheir ends by a weak burstable construction; a barrier film ofstretch-formable material adhered over said support member and flaps andover the opening within said edge area, a layer of glue between saidflaps and said barrier film characterized in that it will permitrelative movement therebetween in vacuum forming procedures, so as toprovide a package blank construction having a rigidity for handling thatis contributed to by adjoining flaps which may be used to provide a cupportion formed through said opening under vacuum forming procedures bybursting said flap ends apart and stretching and moving said barrierfilm relative to the flap and into the cup portion shape that remainssupported and adhered to said flap after said forming.

11. A package blank construction for use in forming one half of agas-tight package that comprises a substantially flat board supportmember, said support member having a circumferential edge area, anopening located within said edge area and at least one flap attachedalong one inner side edge of said circumferential edge area andextending into the opening, a stretch-formable barrier film positionedover said edge portion, said flap and the opening, said barrier filmbeing afiixed to said support member completely around saidcircumferential edge portion, a layer of glue between said flap and aportion of said barrier film, said glue holding the flap and filmadjacent to one another, whereby the package blank which is a bondedtogether unit for handling is adapted to be formed into a pocket shapedpackage part having said flap formed at an angle to said circumferentialedge portion of said film formed into an enclosing pocket a portion ofwhich lies adjacent to said flap and is supported by the flap.

12. A package blank construction as set forth in claim 11 wherein saidglue is of a type having a low resistance to shear so as to permitrelative sliding movement between said film and said flap.

13. A package blank construction as set forth in claim 11 wherein saidglue is a heat sensitive glue which is softenable under heat ofconventional vacuum forming procedures to allow the relative movementbetween said film and said flap during forming of the pocket shapedpackage part.

14. A package blank construction as set forth in calim 11 having a flapsecured to each of the inner edges of said circumferential edge area.

15. A package blank as set forth in claim 14 wherein each said fiap isspaced from an adjacent flap by a gap.

16. A gas-tight package for food comprising a substantially flat bottomportion, a barrier coating adhered to said bottom portion, a top supporthaving an opening therein, a stretch-formed barrier film substantiallyimpermeable to the passage of oxygen adhered to the top support andextending upwardly through said opening to form a pocket portion toreceive the food, said barrier film and said barrier coating beingsealed together around the package circumference to form a gas-tightpackage, and at least one flap on said top support extending at an angleinwardly of said opening, said flap being in protective relation withsaid pocket portion of said barrier film.

17. A gas-tight package as set forth in claim 16, with a flap on eachinside edge of the opening and at least one of said flaps forming arounded corner with said top support at the juncture of said flap withsaid top support so that the film forming the pocket portion isprotected from sharp edges.

18. A gas-tight package as set forth in claim 16 wherein a glue isadhered between and to said flap and barrier film to permit a relativemovement therebetween during forming of said pocket portion.

-19. A gas-tight package as set forth in claim 18 wherein said glue is aheat sensitive vinyl emulsion type glue.

20. A gas-tight package as set forth in claim 16 further comprising aninert gas within said pocket portion.

21. A gas-tight package as set forth in claim 16 whereing a vacuumexists in said pocket portion.

22. A gas-tight package as set forth in claim 16 further comprising asealant coating on the peripheral area of said barrier film about saidopening for forming a circumferential seal about the package periphery.

23. A gas-tight package as set forth in claim 16 wherein said barrierfilm is a vinylidene chloride polymer.

24. A gas-tight package as set forth in claim 16 wherein said flap isprecreased along a line about which said fiap extends from said topsupport.

25. A gas-tight package for food comprising a bottom package portion anda top package portion in sealed relation to each other about theperipheries thereof; at least said top package portion having an openingtherein, a thin flexible stretch-formed barrier film substantiallyimpermeable to the passage of oxygen adhered to said support andextending upwardly through said opening to form a pocket portionreceiving the food, and a rounded edge bearing surface on at least oneedge of said top package portion about said opening in supportingrelation with said barrier film to protect said barrier film.

26. A gas-tight package as set forth in claim 25 further comprising atleast one flap secured to at least one edge of said top package portion,said rounded edge bearing surface being formed at the juncture of saidflap with said top package portion, said flap extending along saidpocket portion in supporting relation therewith.

27. A gas-tight package as set forth in claim 26 further comprising aglue between said flap and said pocket portion, securing said flap tosaid pocket portion, said glue extending at least partially over thesurface of said flap facing said pocket portion.

28. A gas-tight package as set forth in claim 26 wherein said bottompackage portion comprises a self-support- 9 10 ing board and a barriercoating across the surface of said 3,036,705 5/ 1962 Haecker 206-78board facing said top package portion. 3,075,329 1/ 1963 Swezey et a1.

References Cited 3,154,215 10/1964 Vesconte 206-46 X 3,173,540 3/1965Lapides 20678 UNITED STATES PATENTS 5 3,183,100 5/1965 Bonini 99174 X2,621,129 12/1952 Ramsbottom et a1. 2,623,826 12/ 1952 Grinstead 99-174DONALD F. NORTON, Primary Examiner 2,945,586 7/1960 Mackes 206-78

